If anyone's wondering why it's not on WiiU, it would cut into VC game sales. MM1-6 are all out on VC, so it makes no sense for them to compete with themselves.
Aside from that, who the hell wants to buy this anyway? "HD" graphics? Give me a break. They could have EASILY done both - updated all 6 games into high color, HD tiles with identical gameplay AND give us the original versions. They did it with Super Turbo, why couldn't Megaman have gotten the same treatment?